Objective To explore the influence of Monascus fermentation on the release of polyphenols from Apocynum venetum L. leaves.Methods Apocynum venetum L. was fermented with Monascus, and the content of polyphenols was measured, followed by transcriptome analysis.Results Total polyphenols, soluble polyphenols, insoluble-bound polyphenols, as well as the content of chlorogenic acid, luteolin, vitexin, and quercetin were taken as evaluation indicators. The results indicated that fermentation on the 8th day significantly increased the release of polyphenols from Apocynum venetum L. leaves. Transcriptome analysis showed that the regulated expression of carbohydrate-active enzymes such as 1,3-β-GT and XTH23, was the main factor contributing to the release of polyphenols from Apocynum venetum L. by Monascus.Conclusion Monascus fermentation can significantly increase the content of polyphenols in Apocynum venetum L., providing a theoretical foundation and technical support for the continued development of high-quality Apocynum venetum L. tea products.